Souvenir Sheet is square format.Although this edition was authorized by the Niger postal administration, it was not sold in Niger, but only distributed to the novelty trade by the Nigerian philatelic agency.
Also in the issue Dolphins (2018.1):
Data entry completed
|Souvenir Sheet Stenella coeruleoalba in digits|
|Face Value:||3,300 West African CFA franc|
Souvenir Sheet Stenella coeruleoalba it reflects the thematic directions:
Marine life, or sea life or ocean life, refers to the plants, animals and other organisms that live in the salt water of the sea or ocean, or the brackish water of coastal estuaries. At a fundamental level, marine life helps determine the very nature of our planet. Marine organisms produce much of the oxygen we breathe. Shorelines are in part shaped and protected by marine life, and some marine organisms even help create new land. Altogether there are 230,000 documented marine species, including over 16,000 species of fish, and it has been estimated that nearly two million marine species are yet to be documented. Marine species range in size from the microscopic, including plankton and phytoplankton which can be as small as 0.02 micrometres, to huge cetaceans (whales, dolphins and porpoises) which in the case of the blue whale reach up to 33 metres (109 feet) in length, being the largest known animal.
For more information about Stenella coeruleoalba, you can search for GOOGLE